JPS6226956B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a so-called unit swing rear wheel suspension system suitable for small motorcycles used for shopping. The purpose is to obtain a power unit with a

In general, a unit swing type rear wheel suspension system integrally combines the engine and a transmission case with rear wheels to form a power unit, which is swingably supported on the vehicle body frame by a lateral support shaft. This simplifies the rear wheel suspension system, and is often used in small and lightweight motorcycles such as family bikes and small scooters.

By the way, motorcycles are distributed in markets around the world, and when designing motorcycles, it is necessary to consider not only domestic but also foreign markets. If we try to supply products with the same specifications to all countries with different customs, people's weights, etc., some countries will have unnecessary strength, which will cause inconvenience in handling due to increased weight, and resources will be wasted. It is easy to end up consuming it. Therefore, this invention aims to strengthen motorcycles designed for lightness and excellent appearance without impairing their lightness or appearance, so that they can be adapted to countries with large bodies or countries where two-seaters are commonly used. It is meant to be.

The present invention will be explained below with reference to illustrated embodiments. FIG. 1 is a side view of a motorcycle to which the present invention is applied, and FIG. 2 is a partial side view showing the main parts on the opposite side. 1 is a car body frame which is assembled by press forming steel plates and welding, and includes a main column 4 extending rearward from a front fork 3 having a front wheel 2, and a main frame 5 extending vertically and welded to the main column 4 at the center. It is made up of. 6 is a seat provided at the upper end of the main frame 5, 7
is a footrest provided at the lower end. A power unit 8 is rotatably suspended below the body frame 1 by a support shaft 9, and the rear of the power unit 8 is connected to the upper part of the main frame 5 by a buffer spring 11. 12 is a rear wheel. Thus, when the rear wheel 12 runs over an obstacle on the ground while the vehicle is running, the buffer spring 11 is compressed, and the power unit 8 rotates counterclockwise (FIG. 1) about the support shaft 9. It is designed to reduce the impact on the vehicle body frame 5.

As shown in FIG. 2, on the opposite side of the power unit 8, an exhaust muffler 13, indicated by a phantom line, is arranged, and is secured with bolts 38, 38. 1
4 is an exhaust pipe.

Figures 3a to 3c show details of the power unit 8, which includes a cylinder, a crank chamber,
It consists of an engine 15 consisting of a transmission gear chamber, etc., and a transmission case 16 extending rearward from the left side of the engine 15, and one end of an axle 17 of a rear wheel 12 is supported at the rear end of the transmission case 16. 18
is a bevel gear fixed to the rear axle 17, and is driven by a transmission shaft 19 connected to the engine 15 through the transmission case 16. 21 is transmission case 1
The rear wheel 12 is braked by a brake attached to 6.
The other end of the rear axle 17 protrudes from the outer surface of the transmission case 16, engages with a boss 23 of the rear wheel via a spline 22, and engages a nut 2 via a rolling bearing 24.
5 is screwed. 20 is a starting kick pedal.

26 is a reinforcing plate made of steel plate, the front end is a bolt,
It is removably fixed to the side of the engine with a nut 27, and extends rearward through the narrow space between the tire 28 and the muffler 13. Reinforcement plate 26
The details are shown in FIGS. 4a to 4e. The reinforcing plate 26 is made by press-forming a steel plate into a long and thin shape, and the peripheral edge is slightly bent to one side to form a flange 29, and a protrusion 31 is formed in the center as shown in c to increase rigidity. is planned. The front end is divided into two parts, each having a hole 32 for a bolt 27. 33 is a support cylinder for the buffer spring 11, and a reinforcing plate 26
and an auxiliary plate 40 spot-welded to this reinforcing plate 26. A recess 34 is formed at the lower rear of the reinforcing plate 26. As shown in FIGS. 3b and 3c, a case 35 fitted with a rolling bearing 24 is inserted into the recess 34 through an elongated hole 39 formed in its flange 36, and the bolt 3 is inserted into the recess 34.
It is tightened at 7. Therefore, the rear axle 17
can be adjusted back and forth along the elongated hole 39, and the other end is supported at a position determined by the transmission case 16 without being eccentric from this position.

As explained above, the present invention forms a power unit by providing a reinforcing plate on the opposite side of the transmission case to the engine, and the axle of the rear wheel is suspended between the transmission case and the reinforcing plate. Rigidity is significantly improved compared to when supporting by holding. In addition, since the reinforcing plate is made of steel plate, its width is narrow and it can be installed in the narrow space between the tire and the muffler, so the installation position of the muffler can be adjusted between vehicles that have the reinforcing plate and those that do not. There is no need to change it, and since the reinforcing plate is placed inside the muffler, it does not make a big change in the appearance and has the effect of not spoiling the aesthetics.

[Brief explanation of the drawing]

The drawings show an example of the present invention, and FIG. 1 is a side view of a motorcycle to which the present invention is applied, and FIG. 2 is a partial side view showing the opposite side. Third
Figures a to c show the power unit, Figure 3a is a plan view showing a partial cross section of the main part, Figure 3b is a side view thereof, and Figure 3c is taken along line C--C in Figure 3b. 4a to 4e show the reinforcing plate, 4a is a plan view, 4b is an inner side view, and 4c is a cross-sectional view along
to e are lines C-C and D-D in Fig. 4b, respectively.
FIG. 8...Power unit, 9...Support shaft, 13...
Silencer, 15... Engine, 16... Transmission case, 17... Rear axle, 26... Reinforcement plate, 28...
Tire, 35...bearing case.

Claims (1)

[Scope of Claims] 1. A transmission case extending rearward is fixedly installed on one left and right side of the engine, one end of the axle of the rear wheel is supported at the rear end of the transmission case, and the transmission case and the transmission case are installed on the other side of the engine. A power unit equipped with a muffler extending symmetrically to the rear is swingably supported below the vehicle body frame by a horizontal support shaft, and a reinforcing plate made of steel plate is detachably attached to the side surface of the engine on the muffler side. A power unit for a motorcycle in which the rear axle of a reinforcing plate is fixedly fixed and extends rearward through a narrow space between a tire and a muffler, and a rear axle is pivotally supported at the rear end. 2. The power unit according to claim 1, wherein the reinforcing plate pivotally supports the rear axle via a removably attached rolling bearing case. 3. The power unit according to claim 1, wherein the reinforcing plate supports the rear axle in a longitudinally adjustable manner.